Ecological Succession Flashcards
What is Ecological succession?
The process in which disturbances may cause gradual replacement by other species
What is Primary succession?
lifeless area with no soil, and almost no vegetation or organisms. Occurs after major disaster
What is secondary succession
disturbance has destroyed an existing community but has left soil intact (forest fires, floods, severe storms)
What are some abiotic factors
Energy, soil characteristics and water
Explain energy flow
passage of energy through components of ecosystem
Explain chemical cycling
the use and reuse of chemical elements within and between the ecosystems such as carbon and nitrogen
What is Primary Production
rate at which an ecosystems producers convert solar energy to chemical energy stored in biomass
What is biomass
the mass of living organic material in an ecosystem
What are 3 biogeochemical cycles
carbon, phosphorus and nitrogen
Explain the nitrogen cycle
nitrogen is converted into many forms, consecutively passing from the atmosphere into the soil, to organisms and back to the atmosphere
What is Nitrogen Fixation
bacteria converts N2 gas to ammonia and nitrates which are used by plants
What is a biome
a major terrestrial or aquatic life zone
explain aquatic biomes
75% of earths surface is covered by water which is determined by salinity/physical factors
What are the Aquatic Biomes?
Freshwater (salinity >1% salinity, lakes , streams, rivers, wetlands)
Marine (~3% salinity, oceans, tidal zones, coral reefs, estuaries)
Explain Freshwater biomes
Cover less than 1% of earth
contain 0.0% of all water and 6% of species
(used for: drinking, crop irrigation, sanitation and industry)
Explain zones of lake and ponds
Photic zone: light available for photosynthesis
Aphotic zone: light levels to low
Benthic zone: bottom of all aquatic biomes
Explain Rivers and streams
Source of streams: clear and cold fast moving, low in nutrients
Downstream: murky and warm, slower and higher in nutrients
explain wetlands
transitional biome between aquatic and terrestrial one
supports the growth of aquatic plants and have very high diversity
Explain the zones of Marine Biomes
Seafloor is known as the benthic zone
In shallow areas, submerged continents (continental shelfs) the photic zone includes pelagic and benthic regions)
What is the pelagic and photic zone in marine biomes
Pelagic zone included zooplankton, fish and marine mammals
Photic zone extends beyond 200m down, sometimes called the twilight zone
What is estuaries
transition between river and the ocean, the salinity ranges between fresh-ocean water
Most productive areas on earth
What is the intertidal zone
ocean meets land, shore is pounded by waves during high tide, bottom is exposed to sun and dying winds during low tidea
What threatens etuaries
Landfills, nutrient pollution, contamination, alteration of freshwater inflow, and non native species
